Saturday, August 28, 2010

Cargo, Maven and the benefits of integrated functional testing

I little while back an ex-colleague mentioned that I should have a look at an open source project called Cargo. So what is Cargo, their mission statement states "Cargo is a thin wrapper that allows you to manipulate Java EE containers in a standard way." and that is exactly what they do.

I went through some maven configurations and practices along with the concept of continuous integration. This article and Cargo make a logical "Part 3". In the above 2 articles there is a lot of emphasis on continuous testing, but with some very large / legacy systems total unit test coverage is something of a luxury and quite often neglected. Depending on the size, type and deployment of the application there will be certain circumstances where to quickly gain, promote and gauge system stability, integration or functional testing will be a much faster and more beneficial practice than retro fitting unit test coverage.

Tools like Selenium, QTP (QuickTestPro) a number of others, allow you to simply record, playback and validate the application. In my current environment and I am sure in a lot of other places, these types of tests are run by people outside the development team, namely testing teams, clients or even business analysts. I personally feel to gain the most benefit out of functional testing and automation tools these need to happen at build time. Having these tests run outside of the standard development environment add extra unneeded iterations, and more external dependencies that can delay a software project. Bringing these type of tests into you build process allow you detect, maintain and repair system issues before influencing the world outside the development environment.

Like everything else surrounding the "continuous integration" philosophy, automation is key. This is were Cargo helps you out. If you already have the other tools like Maven and Hudson setup it is very quick to integrate and benefit from Cargo.

My environment runs on Weblogic, so that is what I will be using as my example, but Cargo supports about all the major web and application servers used. So this should work for anyone.

Maven has the concept of phases which can be thought of like a collection of goals. A full list of the phases of Maven is available here: Lifecycle Reference

The 3 we are interesting in with regards to Cargo are:pre-integration-test
perform actions required before integration tests are executed. This may involve things such as setting up the required environment.integration-test
Process and deploy the package if necessary into an environment where integration tests can be run.post-integration-test
Perform actions required after integration tests have been executed. This may including cleaning up the environment.

So any phase higher than ’pre-integration-test’ will trigger the deployment to your application server.

Cargo can only stop and start local application servers, deployments can take place remotely, not all application servers have "deployers", detail for these are on the Cargo site. The one feature I am very happy with is the server properties. You can from within you POM configure all the required, JDBC, JMS, and JVM settings you require for your application server to function, which is awesome. In my examples I just needed JVM and JDBC settings, but theoretically you should be able to configure most things you may require.

You could integrate the Cargo plugin into your existing POMs, I prefer to keep it separate. I am not including any Selenium configuration to keep this post about Cargo. However here is a very nice Maven Selenium Guide.

So for the local server configuration, this will startup the application server, create the JDBC configuration and deploy the war.